High-precision voltage stabilizing source circuit with zero temperature coefficient

Abstract

The invention discloses a high-precision voltage stabilizing source circuit with a zero temperature coefficient, and relates to the field of voltage stabilizing source circuits, the high-precision voltage stabilizing source circuit comprises a voltage stabilizing unit, a first current source unit and a second current source unit which are adaptively connected, the first current source unit is used for generating a first current I1 with a positive temperature coefficient, and the second current source unit is used for generating a second current I2 with a negative temperature coefficient. The second current source unit is used for generating a second current I2 with a negative temperature coefficient; and based on the first current I1, the second current I2 and element parameters of the voltage stabilizing unit, the voltage stabilizing unit generates a reference voltage VREF with a zero temperature coefficient. The voltage stabilizing source circuit has a zero temperature coefficient and high output precision.

Description

Technical Field

[0001] The invention relates to the technical field of voltage stabilizing source circuits, in particular to a high-precision voltage stabilizing source circuit with a zero temperature coefficient. Background Art

[0002] With the development of society and the advancement of science and technology, the demand for various high-precision power supplies is increasing. Voltage stabilizer circuits are widely used in DC-DC (direct current-to-direct current converter) and AC-DC (alternating current-to-direct current converter) in various fields. Figure 1 The circuit schematic diagram of a conventional voltage-stabilizing source circuit is shown. When performing TRIM (trim), the voltage-stabilizing source circuit generally adjusts the resistance value of resistor R5 through a fuse to fine-tune the reference voltage, that is, adjust the output accuracy of the voltage-stabilizing source circuit. However, the change in the resistance value of resistor R5 affects not only the output accuracy but also the temperature coefficient of the voltage-stabilizing source circuit. Therefore, in the prior art, during TRIM, only one of the output accuracy and the temperature coefficient can be guaranteed to reach the target parameter, which brings great inconvenience to production testing and application.

[0003] At the same time, the voltage-stabilizing source circuits currently on the market are all prepared using bipolar technology. Affected by the preparation platform, the withstand voltage value of the bipolar process is much smaller than that of the BCD process. Therefore, the traditional voltage-stabilizing source circuit can no longer meet the needs of some high-voltage output applications. Usually, the transformer needs to increase the winding to reduce the voltage to solve such problems, which brings inconvenience to production and increases costs. In addition, since the transistor amplification factor under the bipolar process is relatively low, the voltage-stabilizing source circuit prepared using the bipolar process generally requires a larger IBE current to stabilize the system. Usually, the operating current requires 1mA, the static current is large, the working loss is large, and the overall stability of the circuit is affected. Summary of the invention

[0004] In view of the above problems and technical requirements, the inventors have proposed a high-precision voltage regulator circuit with a zero temperature coefficient. The technical solution of the present invention is as follows:

[0005] A high-precision voltage-stabilizing source circuit with a zero temperature coefficient comprises a voltage-stabilizing unit, a first current source unit and a second current source unit that are adaptively connected, wherein:

[0006] The first current source unit is used to generate a first current I having a positive temperature coefficient 1 The second current source unit is used to generate a second current I having a negative temperature coefficient 2 ;

[0007] Based on the first current I 1 The second current I 2 and component parameters of a voltage stabilizing unit, which generates a reference voltage VREF with a zero temperature coefficient.

[0008] A further technical solution is that the first current source unit includes a power device Q1, n power devices Q2 and a resistor R2;

[0009] All power devices Q2 are connected in parallel, the second electrode of the power device Q1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the second electrodes of all power devices Q2, the first electrodes of all power devices Q2 are connected to the first electrode of the power device Q1, the size of the power device Q2 is the same as the size of the power device Q1, and the first current I 1 satisfy:

[0010]

[0011] Wherein, VBE1 represents the voltage between the second electrode and the first electrode of the power device Q1, VBE2 represents the voltage between the second electrode and the first electrode of the power device Q2, VT represents the thermal voltage, and R2 represents the resistance value of the resistor R2.

[0012] A further technical solution thereof is that it further includes a first current mirror unit, wherein the first current mirror unit includes a power device Q3 and a power device Q4, wherein:

[0013] The third electrode of the power device Q4 is connected to the second electrode, the first electrode of the power device Q3 is connected to the first electrode of the power device Q4, the second electrode of the power device Q3 is connected to the second electrode of the power device Q4, and the third electrode of the power device Q3 is connected to the first electrodes of all the power devices Q2 and the first electrode of the power device Q1.

[0014] A further technical solution is that the second current source unit includes a power device Q5 and a resistor R6, wherein:

[0015] One end of the resistor R6 is connected to the first electrode of the power device Q5 and is grounded. The second electrode of the power device Q5 is connected to the other end of the resistor R6. 2 satisfy:

[0016]

[0017] Wherein, VBE5 represents the voltage between the second electrode and the first electrode of the power device Q5, and R6 represents the resistance value of the resistor R6.

[0018] A further technical solution is that it further includes a second current mirror unit, wherein the second current mirror unit includes a power device P4, a power device P5, a power device N3 and a resistor R5, wherein:

[0019] The first electrode of the power device N3 is connected to the other end of the resistor R6 and the second electrode of the power device Q5, the second electrode of the power device N3 is connected to one end of the resistor R5 and the third electrode of the power device Q5; the third electrode of the power device N3 is connected to the second electrode and the third electrode of the power device P5;

[0020] The first electrode of the power device P5 is connected to the other end of the resistor R5 and the first electrode of the power device P4, the second electrode of the power device P4 is connected to the second electrode of the power device P5, and the third electrode of the power device P4 is connected to the first electrode of the power device Q4.

[0021] A further technical solution is that it further includes a third current mirror unit, wherein the third current mirror unit includes a power device P1, a power device P2 and a power device P3, wherein:

[0022] The first electrode of the power device P1 is connected to the first electrode of the power device P2 and the first electrode of the power device P3, the second electrode of the power device P1 is connected to the second electrode of the power device P2 and the second electrode of the power device P3, the third electrode of the power device P1 is connected to the third electrode of the power device Q1, and the third electrode of the power device P2 is connected to the second electrode.

[0023] A further technical solution is that the voltage stabilizing unit includes a power device Q6, a resistor R1, a resistor R3 and a resistor R4, wherein:

[0024] One end of the resistor R3 is connected to the second electrode of all power devices Q2, the other end of the resistor R3 is connected to the third electrode of the power device Q4, the third electrode of the power device Q6 is connected to the third electrode of the power device P3, and the first electrode of the power device Q6 is connected to one end of the resistor R2 and the second electrode of the power device Q1 through the resistor R1;

[0025] One end of the resistor R4 is connected to the first electrode of the power device Q3, the first electrode of the power device Q4 and the third electrode of the power device P4, and the other end of the resistor R4 is grounded;

[0026] The reference voltage VREF satisfies:

[0027] VREF=VBE6+VBE4+I 1 (R1+R2+R3)+(I 2 +2I 1 )R4

[0028] Among them, VBE6 represents the voltage between the second electrode and the first electrode of the power device Q6, VBE4 represents the voltage between the second electrode and the first electrode of the power device Q2, R1 represents the resistance value of the resistor R1, R3 represents the resistance value of the resistor R3, and R4 represents the resistance value of the resistor R4.

[0029] A further technical solution thereof is that it further includes a driving compensation unit and a power device Q7, wherein the driving compensation unit controls the conduction state of the power device Q7 based on the conduction state of the power device Q1;

[0030] The second electrode of the power device Q7 is connected to the output end of the driving compensation unit, the first electrode of the power device Q7 is grounded, and the second electrode of the power device Q7 is connected to the first electrodes of the power devices P1, P2 and P3.

[0031] A further technical solution is to use a bipolar process or a BCD process to prepare the voltage stabilizing source circuit;

[0032] When the voltage-stabilizing source circuit is prepared by a bipolar process, the power device P1, the power device P2, the power device P3, the power device P4 and the power device P5 are PNP-type transistors, and the power device Q7 and the power device N3 are NPN-type transistors;

[0033] When the voltage-stabilizing source circuit is prepared by the BCD process, the power devices P1, P2, P3, P4 and P5 are high-voltage PMOS tubes, and the power device Q7 and the power device N3 are high-voltage NMOS tubes.

[0034] A further technical solution is that when the voltage stabilizing source circuit is prepared by the BCD process, the voltage stabilizing source circuit further includes a high-voltage isolation unit, and the high-voltage isolation unit includes a high-voltage NMOS tube N1, a high-voltage NMOS tube N2 and a high-voltage PMOS tube P6, wherein:

[0035] The source of the high-voltage NMOS tube N1 is connected to the third electrode of the power device Q1, the drain of the high-voltage NMOS tube N1 is connected to the third electrode of the power device P1, the gate of the high-voltage NMOS tube N1 is connected to the gate of the high-voltage NMOS tube N2 and the gate of the high-voltage PMOS tube P4, the source of the high-voltage NMOS tube N2 is connected to the third electrodes of all the power devices Q2, the drain of the high-voltage NMOS tube N2 is connected to the third electrode of the power device P2, the source of the high-voltage PMOS tube P4 is connected to the third electrode of the power device Q6, and the drain of the high-voltage PMOS tube P4 is grounded.

[0036] The beneficial technical effects of the present invention are:

[0037] The voltage stabilizing source circuit provided by the present invention can be based on the first current I 1 , the second current I 2 The reference voltage VREF with zero temperature coefficient is generated by the component parameters of the voltage stabilizing unit, so that the voltage stabilizing source circuit can be adjusted without affecting the temperature coefficient, so that it has higher output accuracy at the same time. In addition, by setting the high-voltage isolation unit, the voltage stabilizing source circuit can be prepared by BCD process, so that the voltage stabilizing source circuit has the characteristics of high withstand voltage and low static current, low working loss, high overall circuit stability, and can meet the application of high-voltage output. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a circuit principle diagram of a traditional voltage-stabilizing source circuit provided by the present invention.

[0039] Figure 2 The circuit diagram of the first embodiment of the high-precision voltage-stabilizing source circuit with zero temperature coefficient provided by the present invention.

[0040] Figure 3 It is a circuit principle diagram of Embodiment 2 of a high-precision voltage-stabilizing source circuit with zero temperature coefficient provided by the present invention. DETAILED DESCRIPTION

[0041] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0042] The present invention provides a high-precision voltage-stabilizing source circuit with a zero temperature coefficient, comprising a voltage-stabilizing unit, a first current source unit and a second current source unit which are adaptively connected, wherein:

[0043] The first current source unit is used to generate a first current I having a positive temperature coefficient 1 The second current source unit is used to generate a second current I having a negative temperature coefficient 2 ;

[0044] Based on the first current I 1 The second current I 2 and component parameters of a voltage stabilizing unit, which generates a reference voltage VREF with a zero temperature coefficient.

[0045] Specifically, the first current I 1 The second current I is proportional to the temperature. 2 Inversely proportional to the temperature, the first current I 1 The size of the second current I 2The size of can be controlled by the component parameters in the second current source unit. Therefore, by configuring the component parameters in the first current source unit, the second current source unit and the voltage stabilizing unit, the reference voltage VREF output by the voltage stabilizing unit can be made unaffected by temperature, that is, have a zero temperature coefficient. The specific forms of the voltage stabilizing unit, the first current source unit and the second current source unit can refer to the following description.

[0046] Furthermore, the first current source unit includes a power device Q1, n power devices Q2 and a resistor R2; all the power devices Q2 are connected in parallel, the second electrode of the power device Q1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the second electrodes of all the power devices Q2, the first electrodes of all the power devices Q2 are connected to the first electrode of the power device Q1, the size of all the power devices Q2 is the same as the size of the power device Q1, and the first current I 1 satisfy:

[0047]

[0048] Wherein, VBE1 represents the voltage between the second electrode and the first electrode of the power device Q1, VBE2 represents the voltage between the second electrode and the first electrode of the power device Q2, VT represents the thermal voltage, and R2 represents the resistance value of the resistor R2. VT=kT / q, k is the Boltzmann constant, q is the electron charge, and T is the absolute temperature. The component parameters of the first current source unit are the resistance value of the resistor R2 and the number of the power devices Q2.

[0049] Specifically, all power devices Q2 are connected in parallel, that is, the first electrodes of all power devices Q2 are connected to each other, the second electrodes of all power devices Q2 are connected to each other, and the third electrodes of all power devices Q2 are also connected to each other. The same size of the power device Q2 and the power device Q1 means that the power devices have the same characteristic size.

[0050] The voltage stabilizing source circuit can be prepared by bipolar process or BCD process, and the type of each power device in the circuit needs to be set according to different preparation processes. In the first embodiment of the present invention, the voltage stabilizing source circuit is prepared by bipolar process. Figure 2 The circuit schematic diagram of the first embodiment is shown. In the first embodiment, the power device Q1 and the power device Q2 are both NPN transistors. For the NPN transistor, the first electrode of the power device Q1 and the power device Q2 is the emitter, the second electrode is the base, and the third electrode is the collector. The base-emitter voltage of the transistor is inversely proportional to the temperature, but since n power devices Q2 are connected in parallel, VBE1-VBE2 is proportional to the temperature, so the first current I flowing through the resistor R2 is generated. 1 The number of power devices Q2 in the first embodiment is n=8, and the first current I1 It can be expressed as VTln8 / R2. It should be noted that: Figure 2 Only one power device Q2 is shown in the figure, which is used to represent the connection relationship between the electrodes of all power devices Q2 and the power device Q1 and the resistor R2.

[0051] Furthermore, the voltage stabilizing source circuit further includes a first current mirror unit, and the first current mirror unit includes a power device Q3 and a power device Q4, wherein:

[0052] The third electrode of the power device Q4 is connected to the second electrode, the first electrode of the power device Q3 is connected to the first electrode of the power device Q4, the second electrode of the power device Q3 is connected to the second electrode of the power device Q4, and the third electrode of the power device Q3 is connected to the first electrodes of all the power devices Q2 and the first electrode of the power device Q1.

[0053] In the first embodiment, the power device Q3 and the power device Q4 are both NPN transistors, and the definitions of the first electrode, the second electrode and the third electrode of the power device Q3 and the power device Q4 are the same as the definitions of the first electrode, the second electrode and the third electrode of the NPN transistor, which are not repeated here. The power device Q3 and the power device Q4 form a current mirror, and the power device Q3 mirrors the current flowing through the power device Q4.

[0054] Furthermore, the second current source unit includes a power device Q5 and a resistor R6, wherein:

[0055] One end of the resistor R6 is connected to the first electrode of the power device Q5 and is grounded. The second electrode of the power device Q5 is connected to the other end of the resistor R6. 2 satisfy:

[0056]

[0057] Wherein, VBE5 represents the voltage between the second electrode and the first electrode of the power device Q5, and R6 represents the resistance value of the resistor R6. In the first embodiment, the power device Q5 is an NPN transistor, and the base-emitter voltage VBE5 of the transistor Q5 is inversely proportional to the temperature, so the current flowing through the resistor R6 has a negative temperature coefficient. The component parameter of the second current source unit is the resistance value of the resistor R6.

[0058] The voltage stabilizing source circuit further includes a second current mirror unit, which includes a power device P4, a power device P5, a power device N3 and a resistor R5, wherein:

[0059] The first electrode of the power device N3 is connected to the other end of the resistor R6 and the second electrode of the power device Q5, the second electrode of the power device N3 is connected to one end of the resistor R5 and the third electrode of the power device Q5; the third electrode of the power device N3 is connected to the second electrode and the third electrode of the power device P5;

[0060] The first electrode of the power device P5 is connected to the other end of the resistor R5 and the first electrode of the power device P4, the second electrode of the power device P4 is connected to the second electrode of the power device P5, and the third electrode of the power device P4 is connected to the first electrode of the power device Q4.

[0061] In the first embodiment, the power devices P4 and P5 are PNP transistors, the power device N3 is an NPN transistor, and the definitions of the first electrode, the second electrode, and the third electrode of the power devices Q3 and Q4 are the same as the definitions of the first electrode, the second electrode, and the third electrode of the NPN transistor, and are not repeated here. The definitions of the first electrode, the second electrode, and the third electrode of the PNP transistor are the same as the definitions of the first electrode, the second electrode, and the third electrode of the NPN transistor. The power devices P4 and P5 form a current mirror, mirroring the current flowing through the resistor R6 to obtain a second current I 2 .

[0062] The voltage stabilizing source circuit further includes a third current mirror unit, and the third current mirror unit includes a power device P1, a power device P2 and a power device P3, wherein:

[0063] The first electrode of the power device P1 is connected to the first electrode of the power device P2 and the first electrode of the power device P3, the second electrode of the power device P1 is connected to the second electrode of the power device P2 and the second electrode of the power device P3, the third electrode of the power device P1 is connected to the third electrode of the power device Q1, and the third electrode of the power device P2 is connected to the second electrode.

[0064] Specifically, in Embodiment 1, the power device P1, the power device P2 and the power device P3 are all PNP transistors, the emitters of the power device P1, the power device P2 and the power device P3 are interconnected and form the cathode end of the voltage regulator circuit, the power device P1, the power device P2 and the power device P3 form a current mirror, and the collector current of the power device P1 is mirrored to the collector of the power device P3.

[0065] Further, the voltage stabilizing unit includes a power device Q6, a resistor R1, a resistor R3 and a resistor R4, wherein one end of the resistor R3 is connected to the second electrode of the power device Q2, the other end of the resistor R3 is connected to the third electrode of the power device Q4, the third electrode of the power device Q6 is connected to the third electrode of the power device P3, the second electrode voltage of the power device Q6 is the reference voltage VREF, and the first electrode of the power device Q6 is connected to one end of the resistor R2 and the second electrode of the power device Q1 through the resistor R1;

[0066] One end of the resistor R4 is connected to the first electrode of the power device Q3, the first electrode of the power device Q4 and the third electrode of the power device P4, and the other end of the resistor R4 is grounded; the reference voltage VREF satisfies:

[0067] VREF=VBE6+VBE4+I 1 (R1+R2+R3)+(I 2 +2I 1 )R4

[0068] Among them, VBE6 represents the voltage between the second electrode and the first electrode of the power device Q6, VBE4 represents the voltage between the second electrode and the first electrode of the power device Q2, R1 represents the resistance value of the resistor R1, R3 represents the resistance value of the resistor R3, and R4 represents the resistance value of the resistor R4.

[0069] Specifically, the power device Q6 in the first embodiment is an NPN transistor, and one end of the resistor R4 is connected to one end of the resistor R6 and the emitter of the transistor Q5 to form the anode end of the voltage stabilizing source circuit. The component parameters of the voltage stabilizing unit include the resistance values ​​of the resistor R1 and the resistor R3. Since (VBE6+VBE4) has a negative temperature coefficient, I 1 =VTln(n) / R2 has a positive temperature coefficient, I 2 =VBE5 / R6 has a negative temperature coefficient, so VBE6+VBE4+I can be obtained by configuring the number n of power devices Q2, the resistance values ​​of resistors R1, R2 and R3. 1 The value of (R1+R2+R3) has nothing to do with temperature. At the same time, the resistance of resistor R6 is configured to make I 2 +2I 1 The value of is independent of temperature, even if VREF has a zero temperature coefficient. At this time, the resistance value of resistor R4 can be adjusted by the fuse during TRIM to fine-tune the reference voltage VREF, so that the voltage regulator circuit has both a zero temperature coefficient and high output accuracy. The typical value of the reference voltage VREF is 2.5V.

[0070] Further, the voltage stabilizing source circuit further includes a driving compensation unit and a power device Q7, wherein the driving compensation unit controls the conduction state of the power device Q7 based on the conduction state of the power device Q1;

[0071] The second electrode of the power device Q7 is connected to the output end of the driving compensation unit, the first electrode of the power device Q7 is grounded, and the second electrode of the power device Q7 is connected to the first electrodes of the power devices P1, P2 and P3.

[0072] Specifically, the power device Q7 in the first embodiment is an NPN transistor, and the input end of the driving compensation unit is connected to the third electrode of the power device Q1 and the third electrode of the power device P1. In actual application, the second electrode of the power device Q6 is used as the reference end of the voltage-stabilizing source circuit. When the voltage loaded on the reference end is greater than VREF, the power device Q6 is turned on, thereby turning on the power device Q1, and the collector of the power device Q1 is pulled down. At this time, the driving compensation unit pulls up the potential of the second electrode of the power device Q7 to turn on the power device Q7, that is, the cathode end and the anode end of the voltage-stabilizing source circuit are connected. On the contrary, when the voltage loaded on the reference end is less than VREF, the power device Q6 is turned off to turn off the power device Q1, and at the same time, the power device Q2 is turned on to pull up the collector potential of the power device Q1. At this time, the driving compensation unit pulls down the potential of the second electrode of the power device Q7 to turn off the power device Q7. The driving compensation unit includes a driving circuit and a compensation circuit commonly used in a voltage-stabilizing source circuit, and the forms of the driving circuit and the compensation circuit can be consistent with the prior art.

[0073] The present invention further provides a second embodiment, in which the voltage stabilizing source circuit is prepared by using a BCD process. Figure 3 The circuit schematic diagram of the second embodiment is shown. The difference between the second embodiment and the first embodiment is that when the BCD (Bipolar-CMOS-DMOS) process is used for preparation, the power device P1, the power device P2, the power device P3, the power device P4 and the power device P5 can be high-voltage PMOS tubes, and the power device Q7 and the power device N3 can be high-voltage NMOS tubes to improve the withstand voltage value of the voltage-stabilizing source circuit. For the high-voltage NMOS tube and the high-voltage PMOS tube, the first electrode is the source, the second electrode is the gate, and the third electrode is the drain.

[0074] Under the BCD process, the power devices P1, P2 and P3 can use high-voltage PMOS tubes to improve the withstand voltage of the voltage-stabilizing source circuit, but the withstand voltage of the triode is usually lower than 25V, which cannot be adapted to the withstand voltage of the high-voltage PMOS tube. In order to enable the power devices Q1, Q2, Q3, Q4 and Q6 to still use NPN-type triodes, when the voltage-stabilizing source circuit is prepared using the BCD process, a high-voltage isolation unit is set in the voltage-stabilizing source circuit, and the high-voltage isolation unit includes a high-voltage NMOS tube N1, a high-voltage NMOS tube N2 and a high-voltage PMOS tube P6, wherein,

[0075] The source of the high-voltage NMOS tube N1 is connected to the third electrode of the power device Q1, the drain of the high-voltage NMOS tube N1 is connected to the third electrode of the power device P1, the gate of the high-voltage NMOS tube N1 is connected to the gate of the high-voltage NMOS tube N2 and the gate of the high-voltage PMOS tube P4, the source of the high-voltage NMOS tube N2 is connected to the third electrode of the power device Q2, the drain of the high-voltage NMOS tube N2 is connected to the third electrode of the power device P2, the source of the high-voltage PMOS tube P4 is connected to the third electrode of the power device Q6, and the drain of the high-voltage PMOS tube P4 is grounded.

[0076] Specifically, the high-voltage PMOS tube P4 is used to clamp the voltage of the collector of the transistor Q6, and the high-voltage NMOS tube N1 and the high-voltage NMOS tube N2 form a common source and common gate structure, so that the source of the NMOS tube N1 and the NMOS tube N2 is at a low voltage, so that the power device Q1, the power device Q2, the power device Q3 and the power device Q4 can still be NPN-type transistors. The withstand voltage of the cathode end of the voltage-stabilizing source circuit prepared by the BCD process in the second embodiment can reach more than 100V, and because the transistor magnification prepared by the BCD process is larger, the MOS tube gain is also larger, and the voltage-stabilizing source circuit prepared by the BCD process can easily ensure that the static current is less than 100uA. While meeting the high-voltage application, the working loss of the circuit is reduced, and the overall stability of the voltage-stabilizing source circuit is improved.

[0077] It should be noted that the terms "first" and "second" herein are only used to distinguish the objects described, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of protection of the present invention.

Claims

1. A high-precision voltage-stabilizing source circuit with zero temperature coefficient, characterized in that: It includes a voltage stabilizing unit, a first current source unit and a second current source unit that are adaptively connected, wherein: The first current source unit is used to generate a first current I1 having a positive temperature coefficient, and the second current source unit is used to generate a second current I2 having a negative temperature coefficient; Based on the first current I1 , the second current I2 and component parameters of the voltage stabilizing unit, the voltage stabilizing unit generates a reference voltage VREF having a zero temperature coefficient.

2. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 1, characterized in that: The first current source unit includes a power device Q1, n power devices Q2 and a resistor R2; All power devices Q2 are connected in parallel, the second electrode of the power device Q1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the second electrodes of all power devices Q2, the first electrodes of all power devices Q2 are connected to the first electrode of the power device Q1, the size of the power device Q2 is the same as the size of the power device Q1, and the first current I1 satisfies: Wherein, VBE1 represents the voltage between the second electrode and the first electrode of the power device Q1, VBE2 represents the voltage between the second electrode and the first electrode of the power device Q2, VT represents the thermal voltage, and R2 represents the resistance value of the resistor R2.

3. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 2, characterized in that: It also includes a first current mirror unit, which includes a power device Q3 and a power device Q4, wherein: The third electrode of the power device Q4 is connected to the second electrode, the first electrode of the power device Q3 is connected to the first electrode of the power device Q4, the second electrode of the power device Q3 is connected to the second electrode of the power device Q4, and the third electrode of the power device Q3 is connected to the first electrodes of all the power devices Q2 and the first electrode of the power device Q1.

4. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 3, characterized in that: The second current source unit includes a power device Q5 and a resistor R6, wherein: One end of the resistor R6 is connected to the first electrode of the power device Q5 and is grounded, the second electrode of the power device Q5 is connected to the other end of the resistor R6, and the second current I2 satisfies: Wherein, VBE5 represents the voltage between the second electrode and the first electrode of the power device Q5, and R6 represents the resistance value of the resistor R6.

5. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 4, characterized in that: It also includes a second current mirror unit, which includes a power device P4, a power device P5, a power device N3 and a resistor R5, wherein: The first electrode of the power device N3 is connected to the other end of the resistor R6 and the second electrode of the power device Q5, the second electrode of the power device N3 is connected to one end of the resistor R5 and the third electrode of the power device Q5; the third electrode of the power device N3 is connected to the second electrode and the third electrode of the power device P5; The first electrode of the power device P5 is connected to the other end of the resistor R5 and the first electrode of the power device P4, the second electrode of the power device P4 is connected to the second electrode of the power device P5, and the third electrode of the power device P4 is connected to the first electrode of the power device Q4.

6. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 3, characterized in that: It also includes a third current mirror unit, which includes a power device P1, a power device P2 and a power device P3, wherein: The first electrode of the power device P1 is connected to the first electrode of the power device P2 and the first electrode of the power device P3, the second electrode of the power device P1 is connected to the second electrode of the power device P2 and the second electrode of the power device P3, the third electrode of the power device P1 is connected to the third electrode of the power device Q1, and the third electrode of the power device P2 is connected to the second electrode.

7. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 3, characterized in that: The voltage stabilizing unit includes a power device Q6, a resistor R1, a resistor R3 and a resistor R4, wherein: One end of the resistor R3 is connected to the second electrode of all power devices Q2, the other end of the resistor R3 is connected to the third electrode of the power device Q4, the third electrode of the power device Q6 is connected to the third electrode of the power device P3, and the first electrode of the power device Q6 is connected to one end of the resistor R2 and the second electrode of the power device Q1 through the resistor R1; One end of the resistor R4 is connected to the first electrode of the power device Q3, the first electrode of the power device Q4 and the third electrode of the power device P4, and the other end of the resistor R4 is grounded; The reference voltage VREF satisfies: VREF=VBE6+VBE4+I1(R1+R2+R3)+(I2+2I1)R4 Among them, VBE6 represents the voltage between the second electrode and the first electrode of the power device Q6, VBE4 represents the voltage between the second electrode and the first electrode of the power device Q2, R1 represents the resistance value of the resistor R1, R3 represents the resistance value of the resistor R3, and R4 represents the resistance value of the resistor R4.

8. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 7, characterized in that: It also includes a driving compensation unit and a power device Q7, wherein the driving compensation unit controls the conduction state of the power device Q7 based on the conduction state of the power device Q1; The second electrode of the power device Q7 is connected to the output end of the driving compensation unit, the first electrode of the power device Q7 is grounded, and the second electrode of the power device Q7 is connected to the first electrodes of the power devices P1, P2 and P3.

9. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 7, characterized in that: The voltage stabilizing source circuit is prepared by using a bipolar process or a BCD process; When the voltage-stabilizing source circuit is prepared by a bipolar process, the power device P1, the power device P2, the power device P3, the power device P4 and the power device P5 are PNP-type transistors, and the power device Q7 and the power device N3 are NPN-type transistors; When the voltage-stabilizing source circuit is prepared by the BCD process, the power devices P1, P2, P3, P4 and P5 are high-voltage PMOS tubes, and the power device Q7 and the power device N3 are high-voltage NMOS tubes.

10. The high-precision voltage-stabilizing source circuit with zero temperature coefficient according to claim 9, characterized in that: When the voltage stabilizing source circuit is prepared by the BCD process, the voltage stabilizing source circuit further includes a high voltage isolation unit, and the high voltage isolation unit includes a high voltage NMOS tube N1, a high voltage NMOS tube N2 and a high voltage PMOS tube P6, wherein: The source of the high-voltage NMOS tube N1 is connected to the third electrode of the power device Q1, the drain of the high-voltage NMOS tube N1 is connected to the third electrode of the power device P1, the gate of the high-voltage NMOS tube N1 is connected to the gate of the high-voltage NMOS tube N2 and the gate of the high-voltage PMOS tube P4, the source of the high-voltage NMOS tube N2 is connected to the third electrodes of all the power devices Q2, the drain of the high-voltage NMOS tube N2 is connected to the third electrode of the power device P2, the source of the high-voltage PMOS tube P4 is connected to the third electrode of the power device Q6, and the drain of the high-voltage PMOS tube P4 is grounded.

Images